Melik Kara

Spatial and temporal variation and air–soil exchange of atmospheric PAHs and PCBs in an industrial region

Abstract It was recently suggested that emissions of some persistent organic pollutants (POPs) are decreasing in former use regions due to emission reductions combined with uncontrolled export, at the expense of regions receiving these substances as obsolete products and wastes. Aliaga industrial region in Izmir, Turkey is one of the regions receiving POPs in the form of scrap iron and old ships to be scrapped. Ambient air samples were collected by passive sampling during four seasons in 2009 and 2010 (winter, spring, summer, and fall) at forty different sites in Aliaga to determine the spatial and seasonal variations of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs). Soil samples were also collected at the air sampling sites during the summer period. Phenanthrene was the most abundant PAH at all sites, and all samples were dominated by low to medium molecular weight PAHs, i.e., fluorene, fluoranthene and pyrene. The spatial distribution of ambient PAH concentrations indicated that the major PAH sources in the region were iron–steel plants, petroleum refinery, and ship dismantling plants. At residential sites, PAH concentrations were higher in winter indicating that wintertime concentrations were mainly affected by residential heating emissions. However, highest atmospheric PCBs concentrations were observed in summer, probably due to increased volatilization from their sources at higher temperatures. Low to medium molecular weight PCBs (tri–, tetra–, penta–CBs) were the most abundant compounds in air for all seasons. Results also indicated that iron–steel plants and ship dismantling facilities were the major PCB emitters in the region. A similar spatial variation was observed for soil PAH and PCB concentrations. Air and soil PAH and PCB concentrations were correlated significantly indicating the interaction of these compartments. Results of the fugacity ratio calculations indicated that local soils generally act as a sink throughout the year for medium to low volatility atmospheric PAHs and PCBs. However, during summer soil becomes a source, especially for volatile PAHs and PCBs.

Biomonitoring the Spatial and Historical Variations of Persistent Organic Pollutants (POPs) in an Industrial Region

Several persistent organic pollutants (POPs) like polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs), and polybrominated diphenyl ethers (PBDEs) were measured in needle, branch, bark, and tree ring samples in pine samples collected at 27 sites (21 industrial, 6 background) in Aliaga industrial region in Turkey. Soil, litter, and air samples were also collected to investigate the relationships between the air and soil, litter, and tree components. Concentrations decreased with distance from the sources and the lowest ones were measured at background sites. The spatial distribution of POPs indicated that the major sources in the region are the iron-steel, ship-breaking, petrochemical plants and the petroleum refinery. Significant correlations between the air concentrations and, soil, litter, and tree components indicated the interaction of these compartments with air. Observed increasing trends of POPs in the tree-ring samples were representative for the variations in anthropogenic emissions and resulting atmospheric concentrations in Aliaga region. These results indicated that tree components, litter and soil could be used to determine the spatial variations while tree rings could be used to investigate the historical trends of atmospheric POPs in a region. POP amounts (mg/ha) stored in different tree components, litter, and soil were also inventoried. Among the tree components, generally, the highest amounts were stored in the stem followed by needles. For the overall inventory, the highest amounts were stored in soil for PCNs, PBDEs, and PCBs while highest PAH amounts were stored in trees, indicating that in addition to soil, vegetation is also an important reservoir for POPs.

Biogenic volatile organic compound (BVOC) emissions from forested areas in Turkey: determination of specific emission rates for thirty-one tree species.

Normalized biogenic volatile organic compound (BVOC) emission rates for thirty one tree species that cover the 98% of national forested areas in Turkey were determined. Field samplings were performed at fourteen different forested areas in Turkey using a specific dynamic enclosure system. The selected branches of tree species were enclosed in a chamber consisted of a transparent Nalofan bag. The air-flows were sampled from both inlet and outlet of the chamber by Tenax-filled sorbent tubes during photosynthesis of trees under the presence of sunlight. Several environmental parameters (temperature, humidity, photosynthetically active radiation-PAR, and CO2) were continuously monitored inside and outside the enclosure chamber during the samplings. Collected samples were analyzed using a gas chromatography mass spectrometry (GC/MS) system equipped with a thermal desorber (TD). Sixty five BVOCs classified in five major groups (isoprene, monoterpenes, sesquiterpenes, oxygenated sesquiterpenes, and other oxygenated compounds) were analyzed. Emission rates were determined by normalization to standard conditions (1000 μmol/m(2)s PAR and 30 °C temperature for isoprene and 30 °C temperature for the remaining compounds). In agreement with the literature, isoprene was mostly emitted by broad-leaved trees while coniferous species mainly emitted monoterpenes. Several tree species such as Sweet Chestnut, Silver Lime, and European Alder had higher monoterpene emissions although they are broad-leaved species. High isoprene emissions were also observed for a few coniferous species such as Nordmann Fir and Oriental Spruce. The highest normalized total BVOC emission rate of 27.1 μg/gh was observed for Oriental Plane while South European Flowering Ash was the weakest BVOC emitter with a total normalized emission rate of 0.031 μg/gh. Monoterpene emissions of broad-leaved species mainly consisted of sabinene, limonene and trans-beta-ocimene, while alpha-pinene, beta-pinene and beta-myrcene were generally emitted by coniferous species. Oxygenated compounds were the third most prominent BVOC group and sesquiterpenes had slightly lower contributions.

Investigation of spatial and historical variations of air pollution around an industrial region using trace and macro elements in tree components.

Several trace and macro elements (n=48) were measured in pine needle, branch, bark, tree ring, litter, and soil samples collected at 27 sites (21 industrial, 6 background) to investigate their spatial and historical variation in Aliaga industrial region in Turkey. Concentrations generally decreased with distance from the sources and the lowest ones were measured at background sites far from major sources. Spatial distribution of anthropogenic trace elements indicated that their major sources in the region are the iron-steel plants, ship-breaking activities and the petroleum refinery. Patterns of 40 elements that were detected in most of the samples were also evaluated to assess their suitability for investigation of historical variations. Observed increasing trends of several trace and macro elements (As, Cr, Fe, Mo, Ni, V, Cu, Pb, Sb, Sn, and Hg) in the tree-ring samples were representative for the variations in anthropogenic emissions and resulting atmospheric concentrations in Aliaga region. It was shown that lanthanides (La, Ce, Pr, Nd, Sm, Gd, Dy, Er, Yb) could also be used for the investigation of historical variations due to specific industrial emissions (i.e., petroleum refining). Results of the present study showed that tree components, litter, and soil could be used to determine the spatial variations of atmospheric pollution in a region while tree rings could be used to assess the historical variations.

Polychlorinated naphthalene (PCN) emissions from scrap processing steel plants with electric-arc furnaces

Polychlorinated naphthalene (PCN) emissions of scrap iron processing steel plants were explored by measuring concentrations in stack gases of five plants, in the atmosphere (n=11) at a site close to those plants, and in soil at several sites in the region (n=40) in Aliaga, Izmir, Turkey. Observed stack-gas Σ32PCN levels from the plants without scrap preheating (189±157ngNm-3, average±SD, n=4) showed that they are substantial PCN emitting sources. Stack-gas Σ32PCN level for the plant with scrap preheating was considerably higher (1262ngNm-3). Similarly, Σ32PCN emission factor for this plant was substantially higher (11.9mgton-1) compared to those without scrap preheating (1.30±0.98mgton-1). Results have also suggested that the investigated steel plants emit large quantities of fugitive particle-phase PCNs. Measured soil Σ32PCN concentrations that are considered to be representative of the atmospheric levels were greatly variable in the region, ranging between 0.003 and 10.02μgkg-1 (dry wt). Their spatial distribution showed that main PCN sources in the region were the iron-steel plants. Ambient air levels (1620±800pgm-3) were substantially higher than ones observed around the world and in the study area verifying that the steel plants with electric arc furnaces (EAFs) are important PCN sources. Investigation of possible mechanisms suggested that the combustion processes also contribute to emissions from EAFs in addition to evaporation of PCNs present in the scrap iron.

Determination of real-world emission factors of trace metals, EC, OC, BTEX, and semivolatile organic compounds (PAHs, PCBs and PCNs) in a rural tunnel in Bilecik, Turkey

A field study was performed in a rural tunnel to determine pollutant concentrations, sources and on road vehicle emission factors (EFs) of particulate matter, trace metals, elemental carbon (EC), organic carbon (OC), benzene, toluene, ethyl benzene and xylenes (BTEX), and polycyclic aromatic hydrocarbons (PAHs). Emission factors (EFs) for polychlorinated naphthalenes (PCNs) and polychlorinated biphenyls (PCBs) were also determined. A 12-day extensive sampling campaign during morning and afternoon periods at inlet and exit stations of the tunnel was conducted. Morphology of the particles was also investigated by Scanning Electron Microcopy (SEM). Correlation analysis, factor analysis and diagnostic PAH ratios were utilized to identify emission sources of trace metals. Identified sources include brake wear (33%), resuspension of road dust (15%), tyre wear (12%), exhaust emissions (10%), and lubricants (9%). Based on the PAH diagnostic ratios, major sources of PAHs were estimated as diesel emissions. EFs were comparable with the literature and varied from 31.5 to 295.4 mg vehicle-1 km-1 with an average of 129.2 ± 80 mg vehicle-1 km-1 for PM2.5. PM2.5-10 EFs varied between 15.9 and 236.1 mg vehicle-1 km-1 with an average of 96 ± 30 mg vehicle-1 km-1. Average EC EFs were 40.3 ± 9.8 mg vehicle-1 km-1 for PM2.5 samples and 19.5 ± 0.5 mg vehicle-1 km-1 for PM2.5-10 samples while OC EFs were 33.7 ± 18 and 15.5 ± 8.4 mg vehicle-1 km-1 for fine and coarse particles, respectively. EFs of elements were generally 2 (Al) to 59 (Mg) times higher than those previously reported in the literature. Compared to literature, relatively higher EFs for Σ13PAHs (range: 48.1-168 μg vehicle-1 km-1, average: 84.3 ± 46.4 μg vehicle-1 km-1) were obtained. BTEX emission factors were in the range of 4.2 ± 4.7 mg vehicle-1 km-1 (m + p-xylene) and 16.7 ± 10.5 mg vehicle-1 km-1 (toluene). Average EFs for ΣPCBs and ΣPCNs were 12.06 ± 5.3 μg vehicle-1 km-1 and 88.9 ± 70.4 ng vehicle-1 km-1, respectively.

Assessment of seasonal and spatial variations of physicochemical parameters and trace elements along a heavily polluted effluent-dominated stream

This study focuses on a heavily polluted effluent-dominated stream that passes through an industrialized region near Izmir, Turkey. The intermittent creek receives domestic and industrial discharges of Kemalpaşa District Center and its neighborhoods and more than 180 factories of the organized industrial zone. A monitoring campaign was conducted on the creek and samples were taken in two different seasons with distinct hydrological characteristics from 20 stations along the creek to quantify the quality status of water and sediment columns. A number of physicochemical parameters, heavy metals, and trace elements were measured by field and laboratory techniques to assess the status of creek’s water and sediment quality. The spatial and temporal variations were determined, and statistical tools were used to conduct an environmental forensic overview along the creek. A geo-accumulation index and a modified heavy metal pollution index were calculated to cumulatively assess the quality of sediment and water columns, respectively. The results revealed that the creek was under significant pollution load from the industrial zone where metal processing, food and beverage production, marble and natural stone manufacturing, and paper production are made. In particular, elements such as Co, Cu, Cd, Mn, Ni, Pb, Zn, and Zr were found to be above the surface water quality standard values. Similarly, B, Cr, Ni, Cu, Zn, and Sn were determined to be in extreme levels in the sediment column with values exceeding the probable effect concentrations.